Using multispectral imagery to map spatially variable sugarcane aphid infestations in sorghum

Authors: BACKOULOU, GEORGES - Oklahoma State University; Elliott, Norman - Norm; GILES, KRISTOPHER - Oklahoma State University; ALVES, TAVVS - Texas A&M University; BREWER, MICHAEL - Texas A&M University; STAREK, MIKE - Texas A&M University

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2018
Publication Date: 3/1/2018
Citation: Backoulou, G.F., Elliott, N.C., Giles, K.L., Alves, T.M., Brewer, M.J., Starek, M. 2018. Using multispectral imagery to map spatially variable sugarcane aphid infestations in sorghum. Southwestern Entomologist. 43(1):37-44. https://doi.org/10.3958/059.043.0122.
DOI: https://doi.org/10.3958/059.043.0122

Interpretive Summary: The sugarcane aphid, Melanaphis sacchari, is an important pest of grain sorghum. Outbreaks of sugarcane aphid were first reported in commercial sorghum fields in Mexico and Gulf Coast region of the United States of America in 2013. The aphid is now a severe pest of sorghum throughout most of the growing region of the crop in the U.S. Multispectral remote sensing can be used effectively to detect plant stress in agricultural crops. The present study is novel in that investigates the utility of multispectral imagery to delineate spatially variable sugarcane aphid infestations in sorghum fields. Multispectral images were acquired from commercial sorghum fields using a multi-spectral digital camera, mounted in an aircraft fuselage. The study showed that it is feasible to detect and spatially delineate patches of sorghum plants infested by sugarcane aphid in sorghum fields using multispectral imagery. The results indicate potential for mapping spatially variable sugarcane aphid infestations in grain sorghum fields, which could prove useful in detecting and monitoring aphid infested fields, and determining where and when insecticide should be applied for sugarcane aphid control in sorghum fields.

Technical Abstract: The sugarcane aphid, Melanaphis sacchari (Zehntner) (Homoptera: Aphididae), is an important pest of grain sorghum (Sorghum bicolor (L) Moench) worldwide. Outbreaks of sugarcane aphid were first reported in commercial sorghum fields in Mexico and Gulf Coast region of the United States of America in 2013. The aphid is now a severe pest of sorghum throughout most of the growing region of the crop in the U.S. The aphid induces stress to the sorghum crop by damaging the plant foliage. Multispectral remote sensing can be used effectively to detect plant stress in agricultural crops. The present study is novel because it investigates the utility of multispectral imagery to delineate spatially variable sugarcane aphid infestations in commercial grain sorghum fields. Multispectral images were acquired from commercial sorghum fields, using Duncan Tech MS3100-CIR, a 3- bands (NIR+RG) digital camera, mounted nadir from an aircraft fuselage. The unsupervised classification of multispectral images for 5 fields was accomplished using ERDAS Imagine. The study indicates that it is feasible to detect and spatially delineate patches of sorghum plants infested by sugarcane aphid in commercial sorghum fields using multispectral imagery. The overall classification accuracy ranged from 89 to 96% for differentiating areas damaged by sugarcane aphid from areas where plants were not damaged. The results indicate high potential for mapping spatially variable sugarcane aphid infestations in grain sorghum fields.